1. Field of the Invention
The present invention relates to a Radiated Spurious Emissions (RSE) performance enhancement apparatus and method of a multi-standby terminal. More particularly, the present invention relates to an apparatus and method for improving RSE performance of the multi-standby terminal supporting 3rd Generation (3G) and/or 4th Generation (4G) service.
2. Description of the Related Art
With the rapid advancement of information communication and semiconductor technologies, a mobile terminal has evolved into a multifunctional device incorporating various functions such as a TeleVision TV function (e.g., Digital Multimedia Broadcasting (DMB) and Digital Video Broadcasting (DVB)), an audio playback function (e.g., Moving Picture Experts Group (MPEG)-1 or MPEG-2 audio layer-3 (MP3)), a video capture function, a data communication function, an Internet access function, and a global positioning function. More particularly, a recently developed mobile terminal supports a multi-standby mode which is capable of communicating with two or more networks simultaneously. The dual-standby terminal connectable to Code Division Multiple Access (CDMA) and Global System for Mobile communication (GSM) networks simultaneously is a representative multi-standby terminal.
The multi-standby terminal is provided with multiple communication modules for communications with the corresponding radio communication networks. Typically, a communication module includes a duplexer (or diplexer), an antenna switch, a Surface Acoustic Wave (SAW) filter, a Power Amplifier Module (PAM), a Receive (RX) module, and a Transmission (TX) module. As a result of the multi-standby terminal being provided with multiple communication modules, there is a lack of installation space in the multi-standby terminal. In order to address this problem, the multi-standby terminal of the related art supporting 3rd Generation (3G) and/or 4th Generation (4G) services is configured with a communication circuit that includes a Front End Module (FEM). However, the multi-standby terminal of the related art is vulnerable to harmonic attenuation. For this reason, the FEM-based multi-standby terminal of the related art has a drawback in that an abnormal spurious wave is generated when all the multiple communication modules operate in a transmission mode or when a communication module is in a monitoring mode while another one is in the transmission mode. That is, the FEM-based multi-standby terminal of the related art deteriorates the Radiated Spurious Emission (RSE) performance. This problem is becoming a significant issue for the FEM-based multi-standby terminal supporting 3G and/or 4G services.